You don't get a second chance to make a first impression.

Your first impression might tell people you're untrustworthy, lacking intelligence, or even promiscuous.

You don't get a second chance to make a first impression. We all hope that when meeting someone new, we don't make a huge goof, like offending that person or saying something stupid.

But even before you have a chance to wow them with your superior intellect or quick wit--before you even open your mouth--people are already making snap judgments about you.

Psychologists call this tendency "thin slicing." Basically, we tend to look for patterns to help us recognize and understand new things. When we meet a new person, it's our natural inclination to make very quick decisions about them with only minimal information. Since we don't have information about that specific person yet, our assessment is based on what we think we know about people we deem to be like them.

For example, it takes people just one-tenth of a second to decide whether they believe a person is trustworthy or not.

See, we have so many decisions to make in a day that if we really thought each one through and assessed all angles and information available to us, we would never get anything done.

So we rely on our past experiences and, yes, our biases to help us make faster decisions.

We tend to believe that wearing thick glasses and speaking in an expressive way are traits of highly intelligent people. When we meet a new person who fits this bill, our first impression is that he or she must be intelligent, too.

Women with visible tattoos are initially perceived as promiscuous and heavy drinkers, even though both of these assessments might be absolutely false.

Even the way you walk into the room gives others the basis for making a decision about you.

And just how important are these snap decisions? Many studies have shown that those initial decisions people make using thin slicing don't change.